The present invention relates to a type of control mechanism for a motor vehicle door that can block the door in at least one intermediate position.
German Patent Application P No. 35 19 203.8, which corresponds to commonly assigned pending U.S. application Ser. No. 850,004, now U.S. Pat. No. 4,689,849, describes a control mechanism for a vehicle door that permits an immediate arresting of the opening vehicle door in any intermediate position through the operation of an inside or outside handle. This control mechanism is designed such that when the handle is operated in the opening direction, the door opens easily. On the other hand, when the handle is operated in the closing direction, the door can be arrested in any arbitrary intermediate position via the control mechanism. A closing of the door takes place easily without operating the handle and no arresting in an intermediate position is possible.
For the simple operating of a door in the range of small opening angles during the initial opening of the door, it is an objective of the present invention to provide a control mechanism by means of which, while the arresting of the door is maintained, an easy, unimpaired opening of the door is also possible.
This and other objectives are achieved by the present invention by providing in a control mechanism of a motor vehicle door, a piston-cylinder unit arranged between the door post and the vehicle door for dampening door opening and closing movements. The piston-cylinder unit exhibit passage openings and communicate two working chambers of opposite effective pressure surfaces of the piston-cylinder unit. Interior valves control the passage openings in response to relative movement of the vehicle door and door post. A control circuit connects the two working chambers separately from the passage openings. The control circuit includes blocking valves controlled by the door handles in such a way that the door can be blocked in at least one intermediate position. Lastly, the present invention includes an overflow duct which fluidly connects the two working chambers when the door is within a predetermined opening range, irrespective of the blocking valve.
In the mechanism according to pending U.S. application Ser. No. 850,004, the door, via the control mechanism, can be arrested during the opening in any arbitrary intermediate position and therefore also during the initial opening when there is a small opening angle. In order for the door to be opened, while the blocking is eliminated, an overflow duct is provided in the present invention between the two working chambers in the cylinder. When the door is opened from the closed position, the piston of the unit dips into this duct and permits an unimpaired exchange of medium between the two working chambers. It is only after a certain opening angle of the door is reached that the blocking is actuated via the control mechanism. In other words, the door handle must be operated again. The angle for the unblocked opening of the door without the operation of the inside handle of the door should be about 30.degree., so that an unhindered exiting from the vehicle is possible for an average person. It was found even at a door opening angle of about 20.degree., that optimal conditions are met for the exiting of an average person.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.